She dates this development from 2005, when Deloitte hired Tommy Thompson, former secretary of health and human services, as chairman of its global healthcare practice; [71] in 2011, Deloitte was ranked No. 1 by revenue in all areas of healthcare consultingâlife sciences, payer, provider, and government health. [72] Tax treaties [ edit ] Tax treaties in Africa â In November 2013, the international development charity ActionAid accused Deloitte of advising large businesses on how they could use Mauritius to avoid potentially hundreds of millions of dollars of tax in some of the poorest countries in Africa.]